Feature Request: Provider Filtering/Matching Endpoint for Synapse

Background
Related to issue FilOzone/filecoin-services#119: transitioning to a unified service provider registry. To improve discoverability for clients/service creators, Synapse should offer an API endpoint for filtering and matching service providers.

Proposal
Introduce an endpoint (e.g., synapse.providerFiltering or synapse.matchProviders) that allows users (client, service creator, dapp buidler, onramps..) to easily search and filter the service provider pool based on product properties and location.

Initial Filtering Criteria:

• Product type
• Location
• Product properties (e.g., sector size, piece size, publisher presence)

Expected Output:

• Returns a list/JSON of matched service providers, including their unique ID, metadata, and relevant service product.
• No ranking/sorting to start with; could consider randomizing the ordering but also okay to leave it to the SDK user?

Reputation/Scoring Integration (Future Expansion Consideration):
-When there exists scoring/reputation services, we can consider adding reputation or scoring metrics to provider matching and filtering/sorting results.